In Australia right now there is currently a Royal Commission into Institutional Responses to Child Abuse. It is a big deal. The federal government has given wide ranging powers to a commissioner to compel people to attend the commission and it has been running for years now, collecting information from victims, parents, community organisations, schools and other institutions.
It is still running so it has not released findings or recommendations yet but what had become clear from the reports so far is that making the victims completely responsible for reporting and pursuing offenders is a strategy that lets kids down and creates more victims.
I work in a school and by law I have to have a Working with Children Check. I would have to have it just to volunteer to help with reading too. It evaluates ANYTHING in my history that could affect my ability to work with children; convictions, charges that did not lead to conviction, apprehended violence orders (restraining orders), allegations, reasons for prior dismissals if they are on record, and any relevant information collected by registration bodies about disciplinary proceedings or employer concerns.
A new employer does not get given the details. They just find out whether or not I am deemed to be a fit person to work with children. It isn't just about what people have actually been caught doing. It is also about patterns of behaviour that suggest risk. A single unsubstantiated accusation or dropped charge would not put someone out of work under this system, but a list of restraining orders and dismissals like the one in that first link would mean someone should never work with kids again.
It may be that organisations like USAG need some sort of external support mechanism that lets them do something useful with the third party information they have. After all, even if they did ban a coach, a committed paedophile would just find themselves an alternate hunting ground. Volunteering, scouts, youth group leader, etc. There is no shortage of opportunity if there is no nation-wide system that actually keeps an eye on people's past behaviour.